| 摘要 |
PURPOSE:To manufacture a filter of high quality, which has curved surfaces at mountain parts and valley parts, by using a press die manufactured easily with high precision by using a sectionally triangular forming die and by performing formation while controlling press conditions. CONSTITUTION:A forming mold 23 in a sectionally triangluar shape determined by slanting planes 24a and 24b succeeding by turns and in the opposite directions is used and while press conditions are controlled, an acrylic resin plate 16, etc., is pressed to form curved surfaces 2c and 2d at mountain and valley parts by drawback movement after the formation. For example, the die 23 of a 0.8mm. pitch P and 3'(minute) angle beta in a sectionally triangular shape is used and under the conditions of 70kg/cm<2> press pressure, 116 deg.C press temperature and 10 second press time, the acrylic resin plate 16 is pressed, thus obtaining a formed body 25 which has curved surfaces 2c and 2d formed by drawback movement. |
